Skin Protection and Vitamin D
The sunscreen debate continues ~ by Katie Gardner
Taste For Life Magazine, April 2006
You're probably aware of recent reports contradicting what we've been hearing
for years about sun exposure. Concerned about deficiencies in vitamin D
(necessary for strong bones), a number of nutrition experts seem to be
challenging the accepted belief that all sun exposure damages skin - and that
sunscreen is a must if you are going to be outside for extended periods of time.
Yet most dermatologists are equally concerned about the growing incidence of
skin cancer. Season, geography, cloud cover, and pollution can all inhibit our
natural production of this important nutrient from sunlight. Although
insufficient sun exposure can decrease D synthesis, sunscreen use continues to
be an essential tool in promoting skin health.
"Sunshine Vitamin" Benefits
Vitamin D aids calcium absorption and helps maintain normal levels of calcium
and phosphorous in the blood. In addition to fighting osteoporosis, this vitamin
prevents the childhood disease rickets. Recent research suggests that D also
helps maintain muscle strength and prevents many chronic health problems,
including cardiovascular disease, Type 1 diabetes, hypertension, multiple
sclerosis, and rheumatoid arthritis.
This fat-soluble vitamin may also help boost the immune system and regulate
cell growth. Biologically active forms of vitamin D3 appear to inhibit several
cancers including breast, colorectal, and prostate. Because vitamin D occurs
naturally n few foods (eggs, some fatty fish, and fish liver oils), milk and
infant formulas in the U.S. are fortified with this vitamin. It's also available
in supplements, so look for D in your daily multiple.
Balancing the Sun's Risks
In many parts of the U.S., careful sun exposure provides many people with
their D requirements, making sunlight a significant source of this vitamin.
"There is no question that sunscreen usage and sun avoidance may
decrease vitamin D levels," says Vincent Deleo, MD, chairman for
dermatology at St. Luke's Roosevelt and Beth Israel Medical Centers. "But
the vast majority of those published reports show 'low but normal' levels."
"Although the syntheses of vitamin D in the body requires ultraviolet
radiation, the Amount of sun exposure adequate to produce the necessary levels
of vitamin D is not known. What we do know is that excessive, unmitigated solar
irradiation can lead to harmful secondary effects including skin cancers,
immunosuppression, and photodamage," explains Dr. Tsao.
Approximately 15 minutes' sun exposure - without sunscreen - two to three
times a week may provide adequate vitamin D for many people, depending on where
you live and other factors. This initial exposure should be followed by
sunscreen with a sun protection factor (SPF) of at least 15. Sunscreen does not
provide a total UV protection, and even the most effective will let in enough UV
light to allow for some vitamin D formation.
Naturals to Choose
Two types of UV radiation are known to damage skin: UVA and UVB light, the
latter of which the body uses to produce vitamin D. An SPF number measures only
UVB protection, and sun protection products are not required to contain UVA
screens, although some natural products do.
The best was to ensure adequate UVA protection? Read the ingredient label.
Oxybenzone, avobenzone, titanium dioxide, and zinc oxide can help keep harmful
UVA rays from damaging skin.
A small pilot study found that applying diluted extracts of green
tea 30 minutes before UV exposure prevented sunburn, protected skin cells
from UV-induced damage, and lessened DNA damage after radiation.
Natural Health Hut
